Online volunteers map Philippines after typhoon Haiyan

Humanitarian OpenStreetMap Team coordinates mapping effort after enormous storm devastated country

The Guardian, 15 Nov 2013

More than 700 volunteers have collaborated to provide rescue workers with high quality maps of areas in the Philippines hit by typhoon Haiyan.

Working on OpenStreetMap, a collaboratively created map of the world – like Wikipedia, but for cartographers – the volunteers have made over 1.5m changes, providing information for humanitarian aid workers on the ground and updating maps to reflect damage from the storm.

The work is co-ordinated by the Humanitarian OpenStreetMap Team (HOT), a volunteer group which lets disaster relief workers set tasks for mapmakers at home. Users who want to help out can log-in to the tasking manager, where they are presented with a list of requests from the team.

Most of these are as simple as tracing the road network of an affected area from pre-existing satellite imagery. One asks users to trace the backbone road network for Masbate Island, in the north of the affected area; another asks the state of buildings and roads in Roxas City, in the west.

The biggest tasks call for huge areas to be covered in exacting detail using pictures of what the area looks like after the storm.

“Use new satellite imagery to trace buildings, infrastructure, areas, natural features and other important visible features of the city of Ormoc,” lists one requests, as well as “map the current state of Tacloban City area after Typhoon Haiyan inflicted heavy damage to buildings, infrastructure and areas”.

With post-typhoon satellite imagery, the volunteers have the task of checking their traced maps against the reality of the situation on the ground. Structures can be marked as damaged or destroyed, and so the volunteers can begin the odd work of undoing the mapping they have already done.

Already, the mapping is showing results. A picture shared by the Red Cross’s Robert Banick shows the massive increase in detail on a map of Tacloban City after volunteers started filling in the gaps:

OpenStreetMap effects
‘After’ map shows details provided after volunteers have filled in the gaps.. Photograph: https:/

The Red Cross has been using volunteers to improve their maps of under-charted areas since the Haitian earthquake in 2010.

Then, OpenStreetMap users improved maps of Port-au-Prince from the barest outline of the major roads in the area to a fully-detailed map of all the roads in the city and its outlying slums .

Thanks to the efforts of the HOT, responders on the ground have been provided with daily updated downloads for GPS systems, and can use the Field Papers service to print physical atlases of the area, for places where connectivity may be low to non-existent.



An extensive Cochlodinium bloom along the western coast of Palawan, Philippines

Rhodora V. Azanzaa, ,Laura T. Davida,Roselle T. Borjaa,Iris U. Baulaa,Yasuwo Fukuyob
a The Marine Science Institute, University of the Philippines, Diliman, Quezon City 1101, Philippines
b Asian Natural Environmental Science Center, The University of Tokyo, Yayoi 1-1-1 Bunkyo-ku, Tokyo 113-8657, Japan


A massive fish kill and water discoloration were reported off the western coast of Puerto Princesa, Palawan, Philippines in March 2005. Phytoplankton analysis revealed a near monospecific bloom of the dinoflagellate, Cochlodinium polykrikoides, with cell concentrations ranging from 2.5 × 105 to 3.2 × 106 cells per liter. Ground truth data were supplemented by processed satellite images from MODIS Aqua Level 2 data (1 km resolution) from January to April 2005, which revealed high surface chlorophyll-a levels (up to 50 mg/m3) offshore of west and southwest Palawan as early as February 2005. The bloom extended 310 km in length and 80 km in width at its peak in March off the central coast (Puerto Princesa). By April, the bloom declined in intensity, but was still apparent along the northern coast (El Nido). Fluctuations in chlorophyll levels off the western coast of Sabah, Malaysia and Brunei during this time period suggested that the bloom was not limited to the coast of Palawan. Satellite imagery from Sabah in late January revealed a plume of chl-a that is believed to be the source of the C. polykrikoides bloom in Palawan. This plume drifted offshore, advected northward via the basin-wide counterclockwise gyre, and reached nutrient-rich, upwelled waters near Palawan (due to a positive wind stress curl) where the dinoflagellate bloomed and persisted for 2 months from March to April 2005.


  • Cochlodinium polykrikoides;
  • Fish kills;
  • Philippines;
  • Remote sensing